1. Field of the Invention
The present invention relates generally to the roll working field, and more particularly to providing a high-speed rolling method that consists of causing a plurality of planetary cross-rolls to rolls a long metal blank across the width thereof, i.e., perpendicularly to the direction in which the metal blank is being fed through the rolls. The present invention relates also to providing a high-speed rolling apparatus that includes a plurality of planetary rolls that are driven to roll a long metal blank across the width thereof, i.e., perpendicularly to the direction in which the metal blank is being fed through the rolls.
2. Description of the Prior Art
One similar prior art method and apparatus employs the process of rolling a long metal blank by moving the rolls across the width of the metal blank as it is being fed through the rolls. This is disclosed by the same inventor as the current applicant in the Japanese patent publication No. 59-46683.
Another similar prior art method and apparatus employs a different rolling process that uses a pair of planetary rolls or a combination of a planetary roller and an anvil in order to roll a long metal blank as it is being fed through the rolls. This process is different from the first mentioned process in that the metal blank is rolled so that it can be elongated in its longitudinal direction.
The prior art method or apparatus, wherein the long metal blank may be rolled across its width while being fed through the rolls, has been used in the roll working industry with great success, but it is difficult to provide the high-speed rolling process because the rolls must undergo a reciprocating motion across the width of the metal blank being rolled while being fed forward. Mass production cannot be achieved with high efficiency. It is also observed that when the rolls are reciprocated across the width of the metal blank, the metal blank may be placed under an alternating rolling stress, and the metal blank may be elongated irregularly across the width. Thus the finished product may contain defects, such as irregularities (wavy formations) along the longitudinal edges on the opposite sides. Furthermore, the metal blank may have a greater rolling pressure on the center than along the longitudinal edges on the opposite sides, and may undergo a greater elongation on each of the opposite edges than in the center as the reduction becomes the greater. The finished product that results from the rolling process may contain wavy formations or cracks along each of the opposite edges, which will degrade the quality of the finished product. As another disadvantage of the rolling process, the metal blank will become hardened in the central area during the rolling process, and the central area will have a greater resistance to deformation than on each of the opposite edges.
In the second prior art method or apparatus, the rolling process uses a set of planetary rollers that is specifically provided for rolling a long metal blank in the direction of the length thereof (that is, in the direction in which the metal blank is being fed forward), and cannot be used for rolling the metal blank across the width thereof. This process has the disadvantage that it cannot provide a great rolling pressure because the backing-up pressures are not sufficient. In the rolling process that uses the set of planetary rollers and an anvil for rolling a long metal blank therebetween in the direction in which it is being fed forward, the set of planetary rollers and the anvil are arranged to permit the metal blank to be placed therebetween. This arrangement has the problem that the set of planetary rollers cannot be mounted rigidly, and the metal blank cannot be rolled across the width thereof. The rolling across the width may be performed by placing a short metal blank between the set of planetary rollers and the anvil at a certain angle with regard to the direction in which it is being fed. In this case, however, the problem is that the set of planetary rollers cannot provide sufficient backing-up pressure. For practical purposes, this rolling process cannot be used to roll a long metal blank across the width thereof.